BALLASTICS BALLASTICS TRAUMA TO THE TRAUMA TO THE

SKULLSKULL

By Clay ChastainBy Clay Chastain

Above: Angry murderer Above: Angry murderer with a ballistic instrument with a ballistic instrument of death.of death.

Introduction to BallisticsIntroduction to Ballistics

• Ballistics is “the science or Ballistics is “the science or study of the motion of study of the motion of projectiles, as bullets, shells, or projectiles, as bullets, shells, or bombs.” In this context, we are bombs.” In this context, we are focusing on bullets and shells.focusing on bullets and shells.

• Ballistics can be divided into Ballistics can be divided into three main categories:three main categories:

1.1. Handguns (Small caliber)Handguns (Small caliber)

2.2. Rifles (Large caliber)Rifles (Large caliber)

3.3. Shotguns (Buckshot/Birdshot)Shotguns (Buckshot/Birdshot)

Types of HandgunsTypes of Handguns

• There are four main types of handguns:There are four main types of handguns:

1.1. Single-shot pistolsSingle-shot pistols

2.2. DerringersDerringers

3.3. Revolvers Revolvers (most common handgun variant in the United States)(most common handgun variant in the United States)

4.4. Auto-loading pistolsAuto-loading pistols

Above: Single-shot pistol, derringer, revolver, auto-loading pistolAbove: Single-shot pistol, derringer, revolver, auto-loading pistol

Handgun AmmunitionHandgun Ammunition• Common types are round nose Common types are round nose

and hollow-point, but other and hollow-point, but other types include semi-wadcutter types include semi-wadcutter and wadcutter (designed for and wadcutter (designed for target use).target use).

• Caliber (diameter of bullet) Caliber (diameter of bullet) ranges from around .22 to .45 ranges from around .22 to .45 typically.typically.

• Common traits of handgun Common traits of handgun ammunition is a relatively low ammunition is a relatively low firing velocity (Magnum is firing velocity (Magnum is slightly below that of a low end slightly below that of a low end rifle).rifle).

• Can have a “jacket” which is a Can have a “jacket” which is a copper coating that reduces copper coating that reduces lead’s deformation upon entry lead’s deformation upon entry to a surface.to a surface.

Left: Round nose Left: Round nose bullet with full bullet with full jacket.jacket.

Below: Hollow-Below: Hollow-point bullet with point bullet with jacket.jacket.

Types of RiflesTypes of Rifles

• There are two main types of rifles:There are two main types of rifles:

1.1. Rifles (bolt-action, semi-automatic)Rifles (bolt-action, semi-automatic)

2.2. Assault rifles (20 round+ and fully-automatic [M16/AK-Assault rifles (20 round+ and fully-automatic [M16/AK-47 are examples of semi-automatic assault rifles]) 47 are examples of semi-automatic assault rifles])

Above: Kar98 (bolt-action), Modified M16 Rifle with belt feeder system (full-auto)Above: Kar98 (bolt-action), Modified M16 Rifle with belt feeder system (full-auto)

Rifle AmmunitionRifle Ammunition

• Almost all rifles use a similar type Almost all rifles use a similar type of bullet which is has a long case of bullet which is has a long case and an elongated, somewhat and an elongated, somewhat pointed bullet to aid in penetration.pointed bullet to aid in penetration.

• Caliber (diameter of bullet) ranges Caliber (diameter of bullet) ranges from around .22 to .308 typically.from around .22 to .308 typically.

• Common traits of handgun Common traits of handgun ammunition is a relatively high ammunition is a relatively high firing velocity (this creates a more firing velocity (this creates a more circular wound usually).circular wound usually).

• Generally bullets have a jacket Generally bullets have a jacket that helps to maintain velocity and that helps to maintain velocity and stability when hitting a surface, stability when hitting a surface, leaving enough force to exit the leaving enough force to exit the opposite side of the head.opposite side of the head.

Left: Center rifle Left: Center rifle round, semi-round, semi-jacketed with jacketed with Silver-Tip.Silver-Tip.

Left: Traditional Left: Traditional assault rifle assault rifle ammunition.ammunition.

Bullet DeformationBullet Deformation

• Bullets can deform in two Bullets can deform in two ways:ways:

1.1. Naturally (on impact)Naturally (on impact)2.2. By design (Mushrooming)By design (Mushrooming)

These scenarios create These scenarios create irregular exit wounds irregular exit wounds such as large holes or such as large holes or shattering of nearby shattering of nearby bone, along with bone, along with disrupting stereotypical disrupting stereotypical bevels.bevels.

Left (top): A Left (top): A natural natural deformation of deformation of a rifle round a rifle round after hitting a after hitting a hard surface.hard surface.

Left (bottom): Left (bottom): An engineered An engineered bullet which bullet which creates a creates a mushroom-mushroom-shaped hole in shaped hole in soft tissue and soft tissue and the skull.the skull.

Types of ShotgunsTypes of Shotguns

• There are many variants of shotguns:There are many variants of shotguns:

1.1. Single-shotSingle-shot

2.2. Over-and-under (one on top of another)Over-and-under (one on top of another)

3.3. Double-barrel (side by side)Double-barrel (side by side)

4.4. Bolt-actionBolt-action

5.5. Lever-actionLever-action

6.6. Pump-actionPump-action

7.7. Auto-loadingAuto-loading

Above: Generic single-shot, SPAS-12 Tactical (Pump-action), Custom over-and-underAbove: Generic single-shot, SPAS-12 Tactical (Pump-action), Custom over-and-under

Shotgun AmmunitionShotgun Ammunition• Can be classified as birdshot or Can be classified as birdshot or

buckshot. Buckshot are larger buckshot. Buckshot are larger pellets with more weight; pellets with more weight; Birdshot are lightweight pellets.Birdshot are lightweight pellets.

• Gauge (the maximum weight of Gauge (the maximum weight of a lead ball) – 10,12, 16, 20, 28.a lead ball) – 10,12, 16, 20, 28.

• Pellets (the solid ball). Birdshot Pellets (the solid ball). Birdshot - #11 .06, #10 .07. Buckshot – 4 - #11 .06, #10 .07. Buckshot – 4 – 00.– 00.

• Because of weight and velocity, Because of weight and velocity, most pellets will penetrate the most pellets will penetrate the skull at closer ranges than that skull at closer ranges than that of rifles or handguns; many of rifles or handguns; many pellets will also bounce around pellets will also bounce around inside the skull, ricocheting inside the skull, ricocheting from their remaining velocity.from their remaining velocity.

Left: Chart Left: Chart showing showing relative size of relative size of bird/buckshotbird/buckshot

Left (top): Left (top): Typical Typical buckshot buckshot shell.shell.

Left (bottom):Left (bottom):

Typical Typical birdshot shell.birdshot shell.

Pellet Ricocheting Pellet Ricocheting

• It is very common for a pellet to ricochet inside the skull It is very common for a pellet to ricochet inside the skull when impacted from a medium to long range shot, when impacted from a medium to long range shot, creating a degree of brain damage as well as some creating a degree of brain damage as well as some cranial deformation (ridges and pits).cranial deformation (ridges and pits).

Wound Beveling

• Upon impact, wounds will generally exhibit beveling. There are three types:

1. Inward – At the site of a bullet’s entry.2. Outward – At the site of a bullet’s exit.3. Reverse – Beveling of the opposite direction on an entry/exit.

Right: A standard exit Right: A standard exit wound bevel on a wound bevel on a frontal.frontal.

Left: A diagram Left: A diagram showing a typical showing a typical bevel in action.bevel in action.

Wound Shape• Wounds can be classified in four

ways: Round, Oval, Keyhole, and Irregular.

• Round holes are direct angle hits usually from higher velocity sources (although pistols at close range are similar).

• Oval holes often come from side angle bullets, or incomplete contact wounds.

• Keyhole wounds occur when a bullet enters at an angle, chipping away bone in a way that resembles an old-fashioned keyhole.

• Irregular wounds are generally those that come from shotguns or weapons with the force to pulverize bone upon impact.

Left (top): A Left (top): A keyhole keyhole wound.wound.

Left (bottom): Left (bottom): The exit and The exit and round entry round entry wound.wound.

Fractures• Fractures can be classified in three

ways: Radiating, Concentric, and Butterfly.

• Radiating fractures start from the entry/exit wound and radiate to the weakest area in order to relieve pressure.

• Concentric fractures are circular rings that form from extreme pressure, such as from rifles.

• Butterfly fractures are bilateral fractures; however, these fractures are generally on long bones, not the skull.

• There are also irregular fractures, such as when the trauma is extreme enough to pulverize bone; usually these are secondary or tertiary fractures, unless caused by a shotgun.

Left (top): A Left (top): A radiating radiating fracture fracture dissipating at dissipating at a suture.a suture.

Left (bottom): Left (bottom): A concentric A concentric fracture.fracture.

Examples of Fleshed Wounds

• Many fleshed wounds look similar, however the difference between a rifle wound (left) and the shotgun wound (right) is in the amount of trauma to the skull (pulverization versus shattering).

Columbine ReenactmentColumbine ReenactmentTaken from the Midland Reporter Taken from the Midland Reporter Telegram and the Odessa American Telegram and the Odessa American newspapers in 2003. newspapers in 2003.

Myself, in black, using a TEC DC 9, a Myself, in black, using a TEC DC 9, a 9mm pistol with an extended clip.9mm pistol with an extended clip.